Processes which use select microorganisms to treat solid, organic, biodegradable waste materials have long been known.
For example, U.S. Pat. No. 3,462,275 to Bellamy discloses a process for biodegrading such organic waste materials as sewage sludge, slaughterhouse effluent and dairy wastes; and U.S. Pat. No. 3,838,198 to Bellamy et al. discloses a process for biodegrading such organic materials as excrement from ruminents.
A thermophilic mixed culture of bacteria which uses methanol for growth was reported by B. Snedecor and C. L. Cooney in the June 1974 issue of Applied Microbiology at pages 1112-1117.
Canadian Patent No. 1,285,510 to Dyadechko et al. discloses a process for using a bacterial composition to recover environmentally-acceptable water and soil from oil-polluted water and soil.
Canadian Patent No. 1,306,433 to Polne-Fuller discloses a process for microbially degrading certain halogenated hydrocarbons.
U.S. Pat. Nos. 4,806,482 and 4,833,086--both to Horowitz--each disclose a novel plasmid and its use in a microbial host, to degrade ethylene dichloride and certain other chloro-aliphatic organic compounds.
Conventional technologies presently used to treat aqueous and other liquid streams include incineration, evaporation, carbon adsorption, advanced and wet-air oxidation, and biological-activated sludge.
Using naturally-occurring microbes and microbial processes to convert ordinarily toxic manufacturing facility by-products and other substances, borne by aqueous streams, to environmentally-safe materials at environmentally-acceptable levels is desirable for a number of reasons.
For example, it is currently of interest to protect our environment, while reducing capital investment and other operating costs associated with doing so. It is also currently of interest to use naturally-occurring microorganisms to provide a cleaner, safer environment.
However, prior to our discovery, the use of biological methods to convert or otherwise "process" certain recalcitrant products as well as manufacturing-facility by-products to environmentally-safe products (and other materials) at environmentally-acceptable levels were, in general, either not known or not economically feasible. (In the biological sense, the term "recalcitrant" is understood to mean resistant to oxidation.)
Furthermore, the biodegradability of an assortment of typical manufacturing-facility by-products is known to vary.
For example, aniline is known to be biodegradable to some extent; and carboxin has been reported to be biodegradable in certain select, ideal environments; but benzothiazole, on the other hand, is presently known as a recalcitrant substance. While, lindane, once also thought to be recalcitrant, has recently been reported as being biodegradable under certain conditions; yet any biodegradability of 2-mercaptobenzothiazole still remains unreported.
Thus, the desire to use microbial processes to treat aqueous and other liquid streams, initially ordinarily considered toxic, for purposes of producing environmentally-neutral aqueous and other liquid streams at environmentally-safe as well as environmentally-acceptable compositional levels, has been and continues to be an ongoing quest.